Air sluice chamber



April 18, 1967 K. P. FRISK 3,314,198

AIR SLUICE CHAMBER Filed June 14, 1965 United States Patent 3,314,198 AIR SLUICE CHAMBER Karl Per Frisk, Gamleby, Sweden, assignor to Licentia Ekman & Brundin, Stockholm, Sweden, a firm of Sweden Filed June 14, 1965, Ser. No. 463,624

Claims priority, application Sweden, June 15, 1964,

3 Claims. (Cl. 52-2) ABSTRACT OF THE DISCLOSURE A sluice chamber between two air spaces of different pressures having a pair of doors at each end of the sluice chamber. Each door is journalled to rotate about a vertical axis located at the middle of the door to divide the same into an inner blade and outer blade. In their sluice passage blocking positions, the outer blades of each pair of doors seal against each other and the adjacent portions of the sluice chamber, while the inner blades are sealingly located in the half cylindrical side chambers in the side walls of the sluice chamber, the pivot axis of each door being located at the center of the adjacent side chamber. The doors are spring biased towards their passage blocking position.

This invention relates to sluice chambers for connecting a so called plastic hall or tent with the ambient atmosphere in a manner to avoid substantial pressure drop in the hall when persons, vehicles or other objects pass into and out of the hall.

The invention relates to sluice chambers of the kind which may be closed at both ends by means of doors rotatable about vertical axes. As a rule the doors must for the reason of safety permit opening from a closed position by being rotated in a direction away from the space having the higher pressure, i.e., the inner space formed by the hall. This means that the higher pressure prevailing on the inner side of a normal door having its pivot axis at one side edge thereof will act opposite a closing movement of the door. In hitherto known sluice chambers of the kind under consideration this tendency of the force resulting from the pressure difference further requires locking means with relatively great locking force for maintaining the doors in an effective closed position to avoid leakage.

The general object of the invention is to provide a sluice chamber in which the pressure difference acting on the doors is reduced to a minimum in order to facilitate the opening and closing the doors and to enable an elfective closed position and thereby reduce leakage loss.

This and other objects are obtained by a sluice chamber having doors constructed and arranged as defined in the appended claims. A suitable embodiment of the invention and a modification thereof is disclosed in the following with reference to the accompanying drawing.

FIG. 1 is a diagrammatic perspective view of a plastic hall provided with a sluice chamber according to the invention, FIG. 2 is a diagrammatic plan sectional view through the sluice chamber illustrating the passage of a truck through the chamber, and FIG. 3 is a diagrammatic cross section of one end of the sluice chamber including at each end two pairs of cooperating doors located one above the other.

With reference to the drawing numeral 1 denotes a semi'cylindrical hall or tent of reinforced sheet plastics which permits exit or entrance through a passage 2 of substantially rectangular cross section and forming a sluice chamber 7 by means of two pairs of doors 3, 4 and 5, 6 at the respective end of the chamber.

3,314,198 Patented Apr. 18, 1967 Numeral 8 denotes a truck, car or other object passing from the interior of the hall and through the sluice chamber, the truck being shown in a position at the open doors 3, 4. The other doors 5, 6 are closed.

Each door is associated with a niche like recess or side chamber 9 in the side walls 2a and 2b of the passage 2. The side chambers 9 are in open communication with the passage 2. A wire net 10 or rib work indicated by dotted lines prevents entrance to the side chambers.

The bottoms and tops and of the sluice chamber and the side chambers are located in a lower and an upper horizontal plane, respectively.

Each door is rotatable about a vertical axis 11 located at the centre of the semi circular side chamber 9.

All doors of the two pairs 3, 4 and 5, 6 are constructed and arranged in the same way and therefore only door 3 is described in detail.

The door 3 is divided into two door blades 12 and 13 of equal size which may be said to form each a door so that the door 3 may be referred to as a door having double width. The blade 12 extends into the side chamber 9 and is provided with sealing strips at its edges for sealing against the bottom, top and side walls of the side chamber. The sealing is such that only a very little leakage may occur, if any, at the edges of the blade 12, particularly when the door is in the closed position which is shown for the doors 5 and 6.

The other blade 13 is also provided with sealing members along its edges to seal against the top and bottom of the sluice chamber, particularly when the doors are in their closed position.

In the closed position of the doors they are positioned in a common vertical plane disposed at right angles to the longitudinal direction of the sluice chamber with their adjacent vertical edges in sealing engagement with each other.

As will be understood from FIG. 2 the door 3 is rotatable from a central closing position, as shown for the doors 5 and 6, to an open position which is about degrees to either side from the central position. In FIG. 2 the doors 3, 4 are shown adjacent their fully open position. Accordingly, the door may be rotated to either side depending on the direction of movement of the passing truck 8 or other vehicle which pushes the doors to their open position.

Each door is urged by elastic or resilient spring members 14 towards the closed position, and thus the doors will return to the closed position when not retained in other position by the passing truck or other object. Such elastic members or door closing devices are known per se but it should be noted that the force required for returning the doors to the closed position and maintaining t hem therein is relatively small for reasons given below.

When both pairs of doors 3, 4 and 5, 6 are closed there is a certain difference in pressure between the pressures in the hall 1, in the sluice chamber and the pressure of the ambient atmosphere. Any pressure difference acting on the opposite sides of the doors 3, 4 and 5, 6, respectively, result in substantially equal forces on the blades 12 and 13 of each door. Thus the air pressure force acting on the blade 13 will be balanced by the air pressure force acting on the blade 14.

When the two doors 3 and 4 are opened for instance by the truck 8, there will be a pressure equalization so that the pressure in the sluice chamber will rise substantially to the same value as in the hall 1. When the doors thereafter are free to rotate they will be brought back to the closed position by the elastic members 14 practically without any resistance from the air.

When the truck further opens and passes the doors 5 and 6, the pressure in the sluice chamber 7 will be decreased substantially to the pressure of the ambient atmosphere. However, the lowered pressure on the inner side of the doors 3, 4 with respect to the pressure in the hall 1 will cause no tendency of rotating the doors 3 and 4 from their closed position for reasons given above.

When the truck has passed out and the doors 5 and 6 have been closed by their elastic members 14, a very little pressure loss in the hall 1 has occurred due to the fact that this loss is substantially equal to what has been obtained due to the pressure rise in the sluice chamber when opening the doors 4 and 3 and thereby connecting the hall 1 with the sluice chamber 7. In closed position of all doors there is very little leakage through the sluice chamber.

In FIG. 3 is diagrammatically shown the doors at each end of a modified sluice chamber. Two pairs of the doors 15, 16 and 17, 18 are disposed one above the other in a common vertical plane when the doors are closed. The adjacent inner door blade between the vertical pivot axes 19 and 20 are freely movable in the passage 2, Whereas the outer door blades are movable within the side chambers of the kind described above.

The invention has been described with reference to a preferred embodiment. However, various modifications are possible Within the scope of the invention. For instance, the recesses or side chambers may also have a rectangular or any other cross section provided that the edges of the outer door blades sealingly engage the Walls of the recesses when the doors are in their closed position.

What I claim is:

1. A sluice chamber connecting a plastic hall or tent which i held erected by an overpressure of the air enclosed by the hall, with the ambient atmosphere, a pair of opposite recesses formed in the side walls of said sluice chamber at each end thereof, a pair of doors located at each end of said chamber and being pivotally mounted for rotation about vertical axes provided approximately at the middle of the respective door to divide the same into an inner blade extending into the adjacent recess and an outer blade, said outer blades of the doors of each pair cooperating sealingly with each other and the adjacent portions of the sluice chamber when the doors are in their closed position in a plane substantially at right angles to the longitudinal direction of the chamber and said inner blades of each pair of cooperating doors being provided to seal against the walls of the respective recess when the doors are in their closed position and spring means which serve to bias the doors to the passage blocking position when displaced.

2. A sluice chamber as defined in claim 1, in which saild recesses are substantially semicircular in cross section to form half cylindrical side chambers having their centres located substantially in the same plane as the side walls of the sluice chamber, and said doors having their pivot axes located at the centres of said side chambers.

3. A sluice chamber as defined in claim 1, in which a number of pairs of cooperating doors are disposed above each other and cooperate sealingly with each other and the walls of the sluice chamber and the recesses when the doors are positioned in one and the same vertical plane for closing the respective end of the sluice chamber.

References Cited by the Examiner UNITED STATES PATENTS 51,345 12/1865 Olsaver et a1. 49-366 2,910,994 11/1959 Joy 522 2,997,106 3/1961 Dutf 52-2 FOREIGN PATENTS 206,245 4/ 1922 Germany.

DAVID J. WILLIAMOWSKY, Primary Examiner.

KENNETH DOWNEY, Examiner. 

1. A SLUICE CHAMBER CONNECTING A PLASTIC HALL OR TENT WHICH IS HELD ERECTED BY AN OVERPRESSURE OF THE AIR ENCLOSED BY THE HALL, WITH THE AMBIENT ATMOSPHERE, A PAIR OF OPPOSITE RECESSES FORMED IN THE SIDE WALLS OF SAID SLUICE CHAMBER AT EACH END THEREOF, A PAIR OF DOORS LOCATED AT EACH END OF SAID CHAMBER AND BEING PIVOTALLY MOUNTED FOR ROTATION ABOUT VERTICAL AXES PROVIDED APPROXIMATELY AT THE MIDDLE OF THE RESPECTIVE DOOR TO DIVIDE THE SAME INTO AN INNER BLADE EXTENDING INTO THE ADJACENT RECESS AND AN OUTER BLADE, SAID OUTER BLADES OF THE DOORS OF EACH PAIR COOPERATING SEALINGLY WITH EACH OTHER AND THE ADJACENT PORTIONS OF THE SLUICE CHAMBER WHEN THE DOORS ARE IN THEIR CLOSED POSITION IN A PLANE SUBSTANTIALLY AT RIGHT ANGLES TO THE LONGITUDINAL DIRECTION OF THE CHAMBER AND SAID INNER BLADES OF EACH PAIR OF COOPERATING DOORS BEING PROVIDED TO SEAL AGAINST THE WALLS OF THE RESPECTIVE RECESS WHEN THE DOORS ARE IN THEIR CLOSED POSITION AND SPRING MEANS WHICH SERVE TO BIAS THE DOORS TO THE PASSAGE BLOCKING POSITION WHEN DISPLACED. 